See Appendix A for a tabular overview of the arterial distribution. The following describes the anatomical course of the coronary arteries. In general, the area of the heart which an artery passes over will be the area that it perfuses. It lies to the left of the middle cardiac vein and empties into the coronary sinus. Posterior cardiac vein – located on the posterior surface of the left ventricle.Middle cardiac vein (posterior interventricular vein) – begins at the apex of the heart and ascends in the posterior interventricular groove to empty into the coronary sinus.It travels within this groove onto the posterior surface of the heart, where it empties into the coronary sinus. Small cardiac vein – located on the anterior surface of the heart, in a groove between the right atrium and right ventricle.Here, it gradually enlarges to form the coronary sinus. It then curves to the left and continues onto the posterior surface of the heart. It originates at the apex of the heart and ascends in the anterior interventricular groove. Great cardiac vein (anterior interventricular vein) – the largest tributary of the coronary sinus.The main tributaries of the coronary sinus are: There are also smaller cardiac veins which pass directly into the right atrium. The cardiac veins drain into the coronary sinus, which in turn, empties into the right atrium. The venous drainage of the heart is mostly through the coronary sinus – a large venous structure located on the posterior aspect of the heart. In 80-85% of individuals, it also branches into the posterior interventricular artery (PIv) posteriorly.įig 2 – Overview of the branching structure of the coronary arteries. The right coronary artery (RCA) branches to form the right marginal artery (RMA) anteriorly. In ~20-25% of individuals, the left circumflex artery contributes to the posterior interventricular artery (PIv). The LCA also gives off the left marginal artery (LMA) and the left circumflex artery (Cx). The left coronary artery (LCA) initially branches to yield the left anterior descending (LAD), also called the anterior interventricular artery. When the heart is relaxed, the back-flow of blood fills these valve pockets, therefore allowing blood to enter the coronary arteries.

The aortic sinuses are small openings found within the aorta behind the left and right flaps of the aortic valve. There are two main coronary arteries which branch to supply the entire heart. They are named the left and right coronary arteries, and arise from the left and right aortic sinuses within the aorta.

Heart blood flow pathway